To determine the influence of hand practice sequence on psychomotor skill acquisition in a glass ceramic onlay preparation among undergraduate dental students.

Effect of bilateral transfer practice on psychomotor skill acquisition among dental students remains unresolved. Bilateral transfer assumed that training one side of the body can also improve performance on the other side. Eligible participants are fourth- to sixth-year undergraduate dental students at the Faculty of Dentistry, Chulalongkorn University during the 2024 to 2025 academic year. The participants were categorized as left- or right-handed based on self-reporting. Participants enrolled two-day study with one-week separating inverval. On the first day, they learn a video presentation on glass ceramic onlay preparation followed by two practice sessions with 2-hour within each session. The practice start with either using non-dominant or dominant hand, followed by the use of non-dominant hand. One week later, they enroll two-hour practical examination on glass ceramic onlay preparation using their non-dominant hand. No practice is allowed during one-week separating interval.

Inclusion Criteria:

1. The fourth- to sixth-year undergraduate dental students at a single setting of school
2. The fifth- and sixth-year students had completed laboratory and lecture courses in operative and fixed dental prosthodontics
3. The fourth-year students are enrolled in their final laboratory and lecture courses in fixed prosthodontics.

Exclusion Criteria:

Undergraduate dental students who have prior experience with onlay preparation in laboratory or clinical settings or those who are unwillingness to adhere to the study protocol.

The enrolled participants would not prefer to declare their onlay preparation score individually.